Tubular film 12 is drawn from a supply (see FIG. 2, number 40) in the direction indicated by arrow A, i.e. downstream, to pass a cutter 14, of any known type selected according to the shear characteristics of the tubular film 12 material. Tubular film 12 is an extruded plastic resin, for example polyvinyl chloride (PVC) or high density polyethylene (HDPE). In the preferred embodiment, a cutter 14 comprises a fixed blade and a movable blade. The movable blade is moved along a linear path that is perpendicular to planes α and β, and the fixed blade resides at a slight angle to the moving blade. A cutter of this type is described in detail in U.S. patent application Ser. No. 10/411,717, owned by the assignee of this application, and incorporated herein by reference. Other forms of cutter, for example a single blade cutter or a hot wire cutter, are considered within the scope of the present invention.
As tubular film 12 is moved forward in the direction of arrow A, a forward portion of tubular film 12 is inserted into forming tube 18a for a selected length beyond cutter 14. Cutter 14 then severs the selected length of tubular film 12 from the supply of tubular film, creating sleeve 22. The selected length of sleeve 22 is typically chosen to substantially equal the length of product 24 to be enwrapped thereby. In other applications, the length of sleeve 22 is selected to be shorter than the length of product 24 so as to enwrap a portion, not the entire length, of product 24. When sleeve 22 has been severed from the supply of tubular film 12, forming tube 18a is moved downwardly to its second position at plane β with sleeve 22 residing therein, placing forming tube 18b in axial alignment with product 24. Product 24 is resting upon support links 28 of conveyor 26. Product 24 is conveyed upon conveyor 26 in the direction indicated by arrow D. As shown, product 24 is relatively long and thin, for example a felt tip pen, and is best handled in horizontal orientation. Support links 28 are preferably formed with a tapered end 29, residing closer to forming tube 18b so as to reduce resistance to the assembly of sleeve 22 onto product 24. It is to be understood that the stiffness and frictional characteristics of sleeve 24 affect the ease of assembly. When described below without regard to being at a level with either plane α or plane β in the apparatus, the forming tube will be designated as forming tube 18. In the preferred embodiment of the invention, support links 28 are manifested as rotatable rollers so that product 24 and sleeve 22 can be rotated in a downstream heat tunnel to uniformly shrink sleeve 22 to snugly enwrap and conform to the contours of product 24. In other embodiments not incorporating a sleeve-shrinking station, support links 28 may be fixed rather than rotatable. Whereas forming tube 18 of the preferred embodiment is moved vertically from a first position that is high to a second position that is low, it is understood that different transitional directions, for example from left to right, would be modifications within the scope of the present invention.
Vertical sleeve handling often involves a tubular machine component into which the cut sleeve is placed prior to discharging onto the product being labeled. A drawback of vertical sleeve handling is that the cut sleeve will fall through the tube unless the tube is matched closely enough to the size of the sleeve to be held in place by friction, or a holding device, e.g. a suction port, is provided. Since the extruded tubular sleeve will vary somewhat from one lot to the next, the vertical holding tube needs to be changed to accommodate the desired tight fit.
The present invention, as will be described below, provides a sleeve applicator that maintains the product and the tubular sleeve in horizontal orientation. Horizontal orientation allows a variation of sleeve diameter without generally requiring a change of sleeve holding tube. A known horizontal sleeve applicator is manufactured by Marburg Industries, Inc. of Vista, Calif.